1. Field of the Invention
This invention relates to a sleeve for driving a fastener, and more particularly to a durable fastener-driving sleeve assembly driven by a rotary driving tool to rotate a fastener.
2. Description of the Related Art
Referring to FIG. 1, a conventional sleeve 1 has a non-circular head-receiving hole 11 engaging fittingly a driving head 102 of a spanner 101, and a non-circular fastener-receiving hole 12 engaging fittingly a bolt 103. A spring-biased ball 104 is disposed on the driving head 102. The aforesaid conventional sleeve 1 suffers from a disadvantage. That is, when used for a long time period, corners of an inner peripheral surface of the sleeve 1 defining the fastener-receiving hole 12 are easily damaged. To solve this problem, the sleeve 1 can be made of a high-rigidity material. However, this results in a substantial increase in the manufacturing cost of the sleeve 1.